1. Field of the Invention
The present invention relates to an ophthalmic measurement apparatus for measuring biological properties of an eye to be examined, such as the number of cells floating in an anterior chamber thereof, a protein concentration therein, or the degree of opacity of a crystalline lens by projecting scanning laser light into the eye and by receiving, for example, light scattered from the eye.
2. Description of the Related Art
Up to now, a flare meter and a flare cell meter have been known as ophthalmic measurement apparatuses, in which laser light is irradiated into an anterior chamber of an eye to be examined and scattered light produced by the scattering of the laser light in the anterior chamber of the eye is received, to thereby perform ophthalmic measurement. The flare meter etc can measure the number of floating cells in the anterior chamber of the eye, and the protein concentration (flare concentration) therein by the above-mentioned measurement.
As conventional techniques related to such a flare meter, there are techniques disclosed in JP 03-264044 A, JP 07-178052 A, and JP 09-084763 A.
However, in the conventional ophthalmic measurement apparatus such as the flare meter, a specific optical relationship is constructed, in which laser light is projected to the eye from an oblique direction with respect to the eyeball axis thereof and the reflected light is received. In addition, it is difficult to detect a measurement point in the anterior chamber of the eye. Therefore, in order to perform alignment for positional adjustment between the eye and the measurement apparatus, a skilled technique is required for an examiner, which is very difficult.
According to JP 03-264044 A and JP 07-178052 A, it is considered to determine the state of alignment so as to facilitate the alignment. However, even though the determination of the state of alignment is preferably performed, if the alignment work is not actually facilitated, a long period of time is required to complete the alignment depending on the skill of the examiner.
Thus, if it takes a long period of time for the completion of the alignment, a total time required for the measurement becomes long, with the result that the burden placed on an examinee who must continue to gaze into a point becomes excessively large.
Accordingly, development of such an apparatus with good operability and usability has been desired, in which alignment adjustment can easily be performed in a short period of time without depending on the skill of the examiner.